This invention relates generally to mobile machines for mixing concrete on-site, and more particularly, to a discharge chute apparatus for use on concrete trucks.
Concrete trucks, such as that described in U.S. Pat. No. 3,310,293, issuing to Harold M. Zimmerman on Mar. 21, 1967, and U.S. Pat. No. 4,406,548, issuing to Paul M. Haws on Sep. 27, 1983, carry supplies, such as aggregate, cement and water, in discrete hoppers from which the supplies are drawn in predetermined ratios to be deposited in a mixing auger apparatus where the combined supplies are mixed and turned into concrete to be discharged from the mixing auger externally of the concrete truck. This mixing auger apparatus is formed from a generally semi-circular flexible housing against which a standard pitch, spiral flighted auger works to not only mix the combined supplies, but to convey the combined supplies, and ultimately the created concrete, to the remote discharge end of the auger.
Other conventional concrete mixer trucks utilize a mixer drum rotatably mounted on the vehicle frame. These drums usually receive a charge of pre-mixed concrete from a central mixing plant and are rotatable to keep the concrete mixture agitated until delivered to the job site. As depicted in U.S. Pat. No. 5,192,178, granted on Mar. 9, 1993, the more modern configurations of these mixer drums orient the discharge opening at a central forward position relative to the vehicle frame to provide the operator located in the operator's cab to control the discharge and delivery of the mixed concrete through a front-mounted discharge chute mechanism without leaving the cab of the truck.
The utilization of the front discharge mixer drums restricts the configuration of the discharge chute apparatus. The discharge chute is preferably operable to deliver the concrete mixture to a distal discharge point that is variable by extending the length of the chute and by swinging the discharge chute apparatus along a generally horizontal range of operation. Improvements have been made in discharge chutes to maximize the overall length of the discharge chute apparatus when in the storage or transport position. For example, U.S. Pat. No. 2,968,382, granted on Jan. 17, 1961, is representative of a pivotal discharge chute frame that positions the discharge chute in an inoperative storage position within the lateral confines of the vehicle. Other collapsible discharge chutes are depicted in the fold-up version of U.S. Pat. No. 3,930,567, granted on Jan. 6, 1976, and in the telescopic version of U.S. Pat. No. 3,157,262, granted on Nov. 17, 1964.
None of the known discharge chutes for concrete trucks combine a maximizing of the effective overall length of the discharge chute with a transport orientation that collapses the entire length of the discharge chute within the limits of the lateral confines of the concrete truck. It would be desirable to provide a discharge chute apparatus that provides a telescopible operation to provide a substantially infinite variation in the position at which the concrete mixture is discharged, up to the maximum length of the discharge chute apparatus, while utilizing telescoping chute sections whose individual length is substantially equal to the overall width of the concrete truck.